In the retail industry, flat bed or horizontal slot scanners, each having a single horizontal window; vertical slot scanners, each having a single upright or vertical window; and bi-optical scanners, each having both a horizontal window and an upright window, have been used to electro-optically read targets, such as one-dimensional bar code symbols, particularly of the Universal Product Code (UPC) type, and two-dimensional bar code symbols, such as PDF417 and QR codes, at full-service, point-of-transaction checkout systems operated by checkout clerks, and/or at self-service, point-of-transaction checkout systems operated by customers, in supermarkets, warehouse clubs, department stores, and other kinds of retailers, for many years. Products to be purchased bear, or are associated with, identifying target symbols and are typically slid by a user across a scanner window, e.g., from right to left, or from left to right, in a “swipe” mode, to a bagging area. Alternatively, the user merely presents the target symbol on, or associated with, the product to, and holds the product momentarily steady at, a central region of a scanner window in a “presentation” mode, prior to placing the product in the bagging area. The choice depends on the type of target, on user preference, and on the layout of the system.
Some checkout systems are laser-based workstations, and project a multitude of laser scan lines through a scanner window. When at least one of the scan lines sweeps over a target symbol associated with a product, the symbol is processed, decoded and read, thereby identifying the product and enabling information, such as the product's price, to be retrieved from a price database. The multitude of scan lines is typically generated by a scan pattern generator which includes a laser for emitting a laser beam at a mirrored component mounted on a shaft for rotation by a motor about an axis. A plurality of stationary mirrors is arranged about the axis. As the mirrored component turns, the laser beam is successively reflected onto the stationary mirrors for reflection therefrom through the scanner window as a scan pattern of the laser scan lines.
Other checkout systems are imager-based workstations, and have one or more solid-state imagers, or image sensors, analogous to those conventionally used in consumer digital cameras. Each imager has a one- or two-dimensional array of photocells or light sensors (also known as pixels), and an imaging lens assembly for capturing return light scattered and/or reflected from a target being imaged through a scanner window over a field of view, and for projecting the return light onto the sensor array to initiate capture of an image of the target over a range of working distances in which the target can be read. The target may be a symbol, as described above, either printed on a label or displayed on a display screen of an electronic device, such as a smart phone. The target may also be a form, such as a document, label, receipt, signature, driver's license, employee badge, or payment/loyalty card, etc., each bearing alphanumeric characters, as well as a picture, to be imaged. Such an imager may include a one- or two-dimensional charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device and associated circuits for producing and processing electrical signals corresponding to a one- or two-dimensional array of pixel data over the field of view. These electrical signals are decoded and/or processed by a programmed microprocessor or controller into data related to the target being electro-optically read, e.g., decoded data identifying the product and enabling information, such as the product's price, to be retrieved from a price database, or into a picture of a target other than a symbol.
Some laser-based workstations and imager-based workstations are provided with a scale for weighing products that are sold on the basis of weight. For example, many fruits, vegetables, meats, cheeses, nuts, fish, bakery items, candies, etc. are offered for sale in a quantity selected by the customer, and the total price of such loose products depends upon the total weight of the selected quantity. The workstation scale includes a weighing platter or platform, in which the above-mentioned horizontal window is typically integrated. The weighing platter has a generally planar upper surface and overlies a scale mechanism, e.g., one or more load cells. During checkout, the product is placed on the weighing platter so that the scale can measure the product weight. Once the product is identified by reading its target, its unit weight price is retrieved from a price database, and the total price is calculated based on the unit weight price and the weight measured by the scale.
However, as advantageous as the use of such scales in combination with a workstation has been, one concern relates to preventing certain weighing platters from tipping during weighing. Some weighing platters have a length (in practice, about nine inches) and a width that generally matches those of the underlying scale mechanism, and these platters are not subject to tipping. However, some retailers, e.g., warehouse clubs, want longer weighing platters, e.g., on the order of twelve inches, to accommodate weighing of their products, some of which are quite long, especially when purchased in bulk. Although these longer weighing platters have the same width as that of the underlying scale mechanisms, the longer weighing platters project past, and have front ends that overhang, the scale mechanisms in length in front of the user. If a product is placed on such an overhanging platter, especially on its front end, then there is a tendency for the longer weighing platter to tip, that is, for the front end of the longer weighing platter to tilt and descend downwardly. If the front end abuts against a stop, e.g., a part of a counter in which the workstation is installed, then the weight measurement will be erroneous, which is unacceptable. Such tipping can also occur if a user merely accidentally leans on the front end of the longer weighing platter.
It is known to try and resist such tipping by making the weighing platters very heavy, i.e., four or more pounds. However, this solution is ineffective against very heavy products, or accidental user leaning, or even lighter products that are dropped on the front end of the weighing platter. It is also known to make different scale mechanisms with different lengths and widths to accommodate those of the weighing platters. However, the scale mechanism is a complex device, and it is not cost effective to manufacture and supply different scale mechanisms of different sizes.
Another concern about the weighing platters relates to cleaning them. The checkout system environment can be quite dusty and dirty. Products successively placed on, and swiped past, the horizontal window on the weighing platter can shed pieces thereof, or can spill, and will therefore contaminate the weighing platter. Periodic, and frequent, cleaning of the weighing platter are therefore essential, especially in a food environment where hygiene and sanitary conditions are paramount.
It is known to remove weighing platters for cleaning by using tools. However, tools may not always be available. Tools also require a certain amount of skill. Certain retail store personnel may not have the requisite skills to handle tools and/or remove the weighing platters.
Accordingly, there is a need to prevent an overhanging weighing platter of a scale at a workstation from tipping during product weighing without requiring the weighing platter to be extra heavy and without requiring the manufacture and supply of different scale mechanisms of different sizes. There is also a need to easily and rapidly mount the weighing platter on, and to easily and rapidly remove the weighing platter from, the scale mechanism, without the aid of tools, for cleaning purposes.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The system and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.